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ARM 嵌入式 系统 设计与实例开发 实验教材 二源码

		st	%g4, [%o0 + %lo( C_LABEL(cputyp) )]

		/* Turn on Supervisor, EnableFloating, and all the PIL bits.
		 * Also puts us in register window zero with traps off.
		 */
		set	(PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2
		wr	%g2, 0x0, %psr
		WRITE_PAUSE

		/* I want a kernel stack NOW! */
		set	C_LABEL(init_task_union), %g1
		set	(TASK_UNION_SIZE - REGWIN_SZ), %g2
		add	%g1, %g2, %sp
		mov	0, %fp			/* And for good luck */

		/* Zero out our BSS section. */
		set	C_LABEL(__bss_start) , %o0	! First address of BSS
		set	C_LABEL(end) , %o1		! Last address of BSS
		add	%o0, 0x1, %o0
1:	
		stb	%g0, [%o0]
		subcc	%o0, %o1, %g0
		bl	1b
		 add	%o0, 0x1, %o0

		/* Initialize the umask value for init_task just in case.
		 * But first make current_set[boot_cpu_id] point to something useful.
		 */
		set	C_LABEL(init_task_union), %g6
		set	C_LABEL(current_set), %g2
#ifdef CONFIG_SMP
		sethi	%hi(C_LABEL(boot_cpu_id4)), %g3
		ldub	[%g3 + %lo(C_LABEL(boot_cpu_id4))], %g3
		st	%g6, [%g2]
		add	%g2, %g3, %g2
#endif
		st	%g6, [%g2]

		st	%g0, [%g6 + AOFF_task_thread + AOFF_thread_uwinmask]

/* Compute NWINDOWS and stash it away. Now uses %wim trick explained
 * in the V8 manual. Ok, this method seems to work, Sparc is cool...
 * No, it doesn't work, have to play the save/readCWP/restore trick.
 */

		wr	%g0, 0x0, %wim			! so we do not get a trap
		WRITE_PAUSE

		save

		rd	%psr, %g3

		restore

		and	%g3, 0x1f, %g3
		add	%g3, 0x1, %g3

		mov	2, %g1
		wr	%g1, 0x0, %wim			! make window 1 invalid
		WRITE_PAUSE

		cmp	%g3, 0x7
		bne	2f
		 nop

		/* Adjust our window handling routines to
		 * do things correctly on 7 window Sparcs.
		 */

#define		PATCH_INSN(src, dest) \
		set	src, %g5; \
		set	dest, %g2; \
		ld	[%g5], %g4; \
		st	%g4, [%g2];
	
		/* Patch for window spills... */
		PATCH_INSN(spnwin_patch1_7win, spnwin_patch1)
		PATCH_INSN(spnwin_patch2_7win, spnwin_patch2)
		PATCH_INSN(spnwin_patch3_7win, spnwin_patch3)

		/* Patch for window fills... */
		PATCH_INSN(fnwin_patch1_7win, fnwin_patch1)
		PATCH_INSN(fnwin_patch2_7win, fnwin_patch2)

		/* Patch for trap entry setup... */
		PATCH_INSN(tsetup_7win_patch1, tsetup_patch1)
		PATCH_INSN(tsetup_7win_patch2, tsetup_patch2)
		PATCH_INSN(tsetup_7win_patch3, tsetup_patch3)
		PATCH_INSN(tsetup_7win_patch4, tsetup_patch4)
		PATCH_INSN(tsetup_7win_patch5, tsetup_patch5)
		PATCH_INSN(tsetup_7win_patch6, tsetup_patch6)

		/* Patch for returning from traps... */
		PATCH_INSN(rtrap_7win_patch1, rtrap_patch1)
		PATCH_INSN(rtrap_7win_patch2, rtrap_patch2)
		PATCH_INSN(rtrap_7win_patch3, rtrap_patch3)
		PATCH_INSN(rtrap_7win_patch4, rtrap_patch4)
		PATCH_INSN(rtrap_7win_patch5, rtrap_patch5)

		/* Patch for killing user windows from the register file. */
		PATCH_INSN(kuw_patch1_7win, kuw_patch1)

		/* Now patch the kernel window flush sequences.
		 * This saves 2 traps on every switch and fork.
		 */
		set	0x01000000, %g4
		set	flush_patch_one, %g5
		st	%g4, [%g5 + 0x18]
		st	%g4, [%g5 + 0x1c]
		set	flush_patch_two, %g5
		st	%g4, [%g5 + 0x18]
		st	%g4, [%g5 + 0x1c]
		set	flush_patch_three, %g5
		st	%g4, [%g5 + 0x18]
		st	%g4, [%g5 + 0x1c]
		set	flush_patch_four, %g5
		st	%g4, [%g5 + 0x18]
		st	%g4, [%g5 + 0x1c]
		set	flush_patch_exception, %g5
		st	%g4, [%g5 + 0x18]
		st	%g4, [%g5 + 0x1c]
		set	flush_patch_switch, %g5
		st	%g4, [%g5 + 0x18]
		st	%g4, [%g5 + 0x1c]

2:		
		sethi	%hi( C_LABEL(nwindows) ), %g4
		st	%g3, [%g4 + %lo( C_LABEL(nwindows) )]	! store final value
		sub	%g3, 0x1, %g3
		sethi	%hi( C_LABEL(nwindowsm1) ), %g4
		st	%g3, [%g4 + %lo( C_LABEL(nwindowsm1) )]

		/* Here we go, start using Linux's trap table... */
		set	C_LABEL(trapbase), %g3
		wr	%g3, 0x0, %tbr
		WRITE_PAUSE

		/* Finally, turn on traps so that we can call c-code. */
		rd	%psr, %g3
		wr	%g3, 0x0, %psr
		WRITE_PAUSE

		wr	%g3, PSR_ET, %psr
		WRITE_PAUSE

		/* First we call prom_init() to set up PROMLIB, then
		 * off to start_kernel().
		 */

		sethi	%hi( C_LABEL(prom_vector_p) ), %g5
		ld	[%g5 + %lo( C_LABEL(prom_vector_p) )], %o0
		call	C_LABEL(prom_init)
		 nop

		call 	C_LABEL(start_kernel)
		 nop
	
		/* We should not get here. */
		call	halt_me
		 nop

sun4_init:
#ifdef CONFIG_SUN4
/* There, happy now Adrian? */
		set	C_LABEL(cputypval), %o2		! Let everyone know we
		set	' ', %o0			! are a "sun4 " architecture
		stb	%o0, [%o2 + 0x4]		

		b got_prop 
		 nop
#else
		sethi   %hi(SUN4_PROM_VECTOR+0x84), %o1
		ld      [%o1 + %lo(SUN4_PROM_VECTOR+0x84)], %o1
		set     sun4_notsup, %o0
		call    %o1	/* printf */
		 nop
		sethi   %hi(SUN4_PROM_VECTOR+0xc4), %o1
		ld      [%o1 + %lo(SUN4_PROM_VECTOR+0xc4)], %o1
		call    %o1	/* exittomon */
		 nop
1:		ba      1b                      ! Cannot exit into KMON
		 nop
#endif
no_sun4e_here:
		ld	[%g7 + 0x68], %o1
		set	sun4e_notsup, %o0
		call	%o1
		 nop
		b	halt_me
		 nop

		__INITDATA

sun4u_1:
		.asciz "finddevice"
		.align	4
sun4u_2:
		.asciz "/chosen"
		.align	4
sun4u_3:
		.asciz "getprop"
		.align	4
sun4u_4:
		.asciz "stdout"
		.align	4
sun4u_5:
		.asciz "write"
		.align	4
sun4u_6:
        	.asciz  "\n\rOn sun4u you have to use UltraLinux (64bit) kernel\n\rand not a 32bit sun4[cdem] version\n\r\n\r"
sun4u_6e:
		.align	4
sun4u_7:
		.asciz "exit"
		.align	8
sun4u_a1:
		.word	0, sun4u_1, 0, 1, 0, 1, 0, sun4u_2, 0
sun4u_r1:
		.word	0
sun4u_a2:
		.word	0, sun4u_3, 0, 4, 0, 1, 0
sun4u_i2:
		.word	0, 0, sun4u_4, 0, sun4u_1, 0, 8, 0
sun4u_r2:
		.word	0
sun4u_a3:
		.word	0, sun4u_5, 0, 3, 0, 1, 0
sun4u_i3:
		.word	0, 0, sun4u_6, 0, sun4u_6e - sun4u_6 - 1, 0
sun4u_r3:
		.word	0
sun4u_a4:
		.word	0, sun4u_7, 0, 0, 0, 0
sun4u_r4:

		__INIT
no_sun4u_here:
		set	sun4u_a1, %o0
		set	current_pc, %l2
		cmp	%l2, %g3
		be	1f
		 mov	%o4, %l0
		sub	%g3, %l2, %l6
		add	%o0, %l6, %o0
		mov	%o0, %l4
		mov	sun4u_r4 - sun4u_a1, %l3
		ld	[%l4], %l5
2:
		add	%l4, 4, %l4
		cmp	%l5, %l2
		add	%l5, %l6, %l5
		bgeu,a	3f
		 st	%l5, [%l4 - 4]
3:
		subcc	%l3, 4, %l3
		bne	2b
		 ld	[%l4], %l5
1:
		call	%l0
		 mov	%o0, %l1

		ld	[%l1 + (sun4u_r1 - sun4u_a1)], %o1
		add	%l1, (sun4u_a2 - sun4u_a1), %o0
		call	%l0
		 st	%o1, [%o0 + (sun4u_i2 - sun4u_a2)]

		ld	[%l1 + (sun4u_1 - sun4u_a1)], %o1
		add	%l1, (sun4u_a3 - sun4u_a1), %o0
		call	%l0
		st	%o1, [%o0 + (sun4u_i3 - sun4u_a3)]

		call	%l0
		 add	%l1, (sun4u_a4 - sun4u_a1), %o0

		/* Not reached */
halt_me:
		ld	[%g7 + 0x74], %o0
		call	%o0			! Get us out of here...
		 nop				! Apparently Solaris is better.

/* Ok, now we continue in the .data/.text sections */

	.data
	.align 4

/*
 * Fill up the prom vector, note in particular the kind first element,
 * no joke. I don't need all of them in here as the entire prom vector
 * gets initialized in c-code so all routines can use it.
 */

	.globl	C_LABEL(prom_vector_p)
C_LABEL(prom_vector_p):
		.word 0

/* We calculate the following at boot time, window fills/spills and trap entry
 * code uses these to keep track of the register windows.
 */

	.align 4
	.globl	C_LABEL(nwindows)
	.globl	C_LABEL(nwindowsm1)
C_LABEL(nwindows):
	.word	8
C_LABEL(nwindowsm1):
	.word	7

/* Boot time debugger vector value.  We need this later on. */

	.align 4
	.globl	C_LABEL(linux_dbvec)
C_LABEL(linux_dbvec):
	.word	0
	.word	0

	.align 8

	.globl	C_LABEL(lvl14_save)
C_LABEL(lvl14_save):
	.word	0
	.word	0
	.word	0
	.word	0
	.word	t_irq14

        .section        ".fixup",#alloc,#execinstr
        .globl  __ret_efault
__ret_efault:
        ret
         restore %g0, -EFAULT, %o0